ANN ARBOR—One of the most powerful positive forces available to parents of teens has a bad reputation: peer pressure.

Yes, moms and dads, University of Michigan researchers find that your young teen-agers' friends—the same folks who tie up your phone lines and empty your refrigerators—are probably doing more good than harm.

"A number of studies done in the past have suggested that one of the main reasons young teens drink, smoke, use illegal drugs and have sex is because of pressure from their friends," says Robert W. Roeser, a research associate at the U-M School of Education. Roeser is part of the research team headquartered at the U-M Institute for Social Research directing the ongoing study of adolescent development in Prince George's County, Md.

"But our study of approximately 1,500 adolescents and their families shows that the vast majority of young teens are not pressured by their friends to drink, smoke, use illegal drugs, or engage in other delinquent behaviors. In fact, friends are much less likely to pressure each other to do wrong than to support each other's efforts to do well."

The Family Survey Study was started in 1991 by the University of Colorado, with funding from the MacArthur Foundation. Now funded by the National Institute of Child Health and Development and conducted by the U-M, it is among the most comprehensive studies of adolescent development ever undertaken, interviewing teen-agers and their parents to gather information about families, teachers, peers and neighborhoods.

Researchers are currently in the field gathering information from the same group of teens, now 11th-graders, and their parents. They hope to interview the group again after they have finished high school, to see what paths they have taken. The sample, which is 62 percent Black, is representative of a full range of socioeconomic situations.

Among the findings on the good and bad influence of friends to emerge from the data analyzed so far:

As seventh-graders, 92 percent said that none of their friends pressured them to have sex; 98 percent said that none of their friends pressured them to drink; and 99 percent said that none pressured them to use illegal drugs.

By eighth-grade, a clear but somewhat smaller majority reported having no experience with negative peer pressure. About 70 percent said that none of their friends pressured them to have sex; 88 percent said that none of their friends pressured them to drink; and 91 percent said that none of their friends pressured them to use drugs.

In addition, most of the seventh-graders and eighth-graders felt that all or almost all of their friends had a positive attitude towards school. For example, 67 percent of seventh- graders said that all or almost all of their friends did well in school, and 75 percent said that all or almost all of their friends were planning to attend college. The percentages of eighth-graders who reported similar feelings of support from friends about school achievement was only slightly lower.

"As children enter adolescence, friends assume a more prominent role in their lives," says Roeser, "and one of the most helpful things parents can do is stay involved and get to know their teen-ager's friends.

"If the friends are involved in positive activities, have good attitudes toward school and aspirations to attend college, parents should do everything they can to encourage the friendship. Parents should also remain open and accepting, realizing a teen's values, not his or her appearance, is what's really important."